Mediterr J Otol 2006:2(1): 19-26

Diagnosis of Ménière’s disease using low-frequency masking

Papadeas Evangelos, Naxakis Stefanos, Doschoris Michael, Mavrilas Dimosthenis, Goumas Panos

Department of Otolaryngology Head and Neck Surgery, University Hospital, University of Patras Patras, Greece otology@med.upatras.gr

Objective: To evaluate low-frequency masking in the early diagnosis of Ménière’s disease.

Patients and methods: Thirty-five patients suffering from Ménière’s disease were examined. The results were compared with that of 10 patients with normal hearing ears and 40 with noise-damaged ears. All examinations were made by the use of a special instrumentation capable of producing a low-frequency sound signal superimposed with a tone burst. We were able to independently change the amplitudes of the 2 applied signals, as well as the phase lag between them from 0° to 360°. Adjusting the 2 amplitudes and the phase lag, the examined individuals heard 2 sounds, 1 as the masking tone and 1 high-frequency tone superimposed on the low-frequency masking.

Results: In normal individuals, the highest masking effect was evident at 250° and the lowest at 360°. A lower masking effect was also evident at 90°. Normal hearing participants had a modulation depth between 20 and 35 dB, while patients with noise damaged ears had an effect about 10 dB and patients with Ménière’s disease had one closer to 0 dB. The instrumentation and method presented in this article show a relatively good clinical diagnostic accuracy because it is capable of diagnosing the basilar membrane stiffness on an almost null modulation depth. Test sensitivity is near 70%.

Conclusion: The developed instrumentation and method can distinguish and diagnose the early stages and acute recurrences of Ménière’s disease. This may lead to a further study of the results of low-frequency masking on the anterior labyrinth in research centers worldwide, in order to reinforce the diagnostic accuracy and strength of this newly developed diagnostic method.